comments and tests for plot_api/helpers.hasParent

Author: alexcjohnson

Diff for: src/plot_api/helpers.js

@@ -485,13 +485,30 @@ exports.manageArrayContainers = function(np, newVal, undoit) {
     }
 };
 
+/*
+ * Match the part to strip off to turn an attribute into its parent
+ * really it should be either '.some_characters' or '[number]'
+ * but we're a little more permissive here and match either
+ * '.not_brackets_or_dot' or '[not_brackets_or_dot]'
+ */
 var ATTR_TAIL_RE = /(\.[^\[\]\.]+|\[[^\[\]\.]+\])$/;
 
 function getParent(attr) {
     var tail = attr.search(ATTR_TAIL_RE);
     if(tail > 0) return attr.substr(0, tail);
 }
 
+/*
+ * hasParent: does an attribute object contain a parent of the given attribute?
+ * for example, given 'images[2].x' do we also have 'images' or 'images[2]'?
+ *
+ * @param {Object} aobj
+ *  update object, whose keys are attribute strings and values are their new settings
+ * @param {string} attr
+ *  the attribute string to test against
+ * @returns {Boolean}
+ *  is a parent of attr present in aobj?
+ */
 exports.hasParent = function(aobj, attr) {
     var attrParent = getParent(attr);
     while(attrParent) {

Diff for: test/jasmine/tests/plot_api_test.js

@@ -7,6 +7,7 @@ var Bar = require('@src/traces/bar');
 var Legend = require('@src/components/legend');
 var pkg = require('../../../package.json');
 var subroutines = require('@src/plot_api/subroutines');
+var helpers = require('@src/plot_api/helpers');
 
 var d3 = require('d3');
 var createGraphDiv = require('../assets/create_graph_div');
@@ -1309,3 +1310,52 @@ describe('Test plot api', function() {
         });
     });
 });
+
+describe('plot_api helpers', function() {
+    describe('hasParent', function() {
+        var attr = 'annotations[2].xref';
+        var attr2 = 'marker.line.width';
+
+        it('does not match the attribute itself or other related non-parent attributes', function() {
+            var aobj = {
+                // '' wouldn't be valid as an attribute in our framework, but tested
+                // just in case this would count as a parent.
+                '': true,
+                'annotations[1]': {}, // parent structure, just a different array element
+                'xref': 1, // another substring
+                'annotations[2].x': 0.5, // substring of the attribute, but not a parent
+                'annotations[2].xref': 'x2' // the attribute we're testing - not its own parent
+            };
+
+            expect(helpers.hasParent(aobj, attr)).toBe(false);
+
+            var aobj2 = {
+                'marker.line.color': 'red',
+                'marker.line.width': 2,
+                'marker.color': 'blue',
+                'line': {}
+            };
+
+            expect(helpers.hasParent(aobj2, attr2)).toBe(false);
+        });
+
+        it('is false when called on a top-level attribute', function() {
+            var aobj = {
+                '': true,
+                'width': 100
+            };
+
+            expect(helpers.hasParent(aobj, 'width')).toBe(false);
+        });
+
+        it('matches any kind of parent', function() {
+            expect(helpers.hasParent({'annotations': []}, attr)).toBe(true);
+            expect(helpers.hasParent({'annotations[2]': {}}, attr)).toBe(true);
+
+            expect(helpers.hasParent({'marker': {}}, attr2)).toBe(true);
+            // this one wouldn't actually make sense: marker.line needs to be an object...
+            // but hasParent doesn't look at the values in aobj, just its keys.
+            expect(helpers.hasParent({'marker.line': 1}, attr2)).toBe(true);
+        });
+    });
+});